Tamper evident seals have been used to increase consumer safety by showing whether a package has been opened after being produced. Embodiments of tamper evident indicators include a pop-up button in the center of a package and a break-away seal connected to the lower edge of a lid. The pop-up button has the disadvantage that it may be difficult to ascertain whether the seal has been broken. The break-away lower lid section may be too sensitive and may break away inadvertently during normal jostling. Alternatively, the break-away lower lid section may be insensitive to tampering or pilfering, and may not break away until after the seal between the closure and the container has been breached. The latter situation raises the possibility that the container may be accessed and resealed without breaking the tamper evident seal. This possibility undermines the purpose behind the tamper-evident seal, thereby reducing consumer confidence in a product sealed in this manner.
The following patents discuss tamper evident seals. U.S. Pat. No. 4,378,894 is believed to describe a tamper-evident screw threaded closure having bridges that fracture from the application of removal torque to the closure prior to breaking the seal between the liner and the container.
U.S. Pat. No. 4,448,318 is believed to describe a screw threaded closure for containers having a tamper-evident ring or band connected to the lower terminal edge of a skirt by at least a pair of fracturable bridge means. The bridge means are oriented in a predetermined manner relative to one another to effect sequential breaking in a given pattern upon relative movement of the cap portion and ring in the direction.
U.S. Pat. No. 4,534,480 is believed to describe a tamper evident closure for use on a screw threaded neck of a container. The closure includes a tamper evident band joined to the cap's sidewall by a plurality of bridge strips that are circumferentially aligned with ratchet teeth on the tamper evident band. During cap removal, the ratchet lugs stop the ratchet teeth and the tamper evident band from moving so that the band is separated from the cap, thereby providing an indication of tampering with the closure.
U.S. Pat. No. 4,567,991 is believed to describe a tamper indicating child resistant package including a screw type closure for use with a container having a threaded neck portion. A tamper indicating means is provided to maintain the lock element in circumferentially aligned relationship relative to the lock member, and is further provided with stop elements to cooperatively engage the stop lugs on the container. The tamper indicating means prevents removal of the closure before separating the tamper indicating means from the remainder of the closure, thereby giving evidence of tampering with the container.
U.S. Pat. No. 4,828,127 is believed to describe a tamper-evident screw-threaded closure in which the skirt of a cap is joined at its lower edge to a band by integral elongated breakable webs. The band has lugs which oppose circumferential, rather than axial, movement in the unscrewing direction.
U.S. Pat. No. 4,936,475 is believed to describe a tamper indicating closure and closure-container package in which a tamper indicating skirt depends from the bottom of the annular wall of a standard threaded cap. The skirt includes a plurality of equally spaced depending ribs that are joined at their extremities by a flexible ring. The ring and the skirt ribs pass over lugs on the container neck when the cap is being threaded onto the closure. When the cap is being unthreaded, the lugs engage the rings to sever them indicating tampering or prior opening.
U.S. Pat. No. 5,320,233 is believed to describe a lug cap or closure that is used in combination with a container for indicating that the container has been opened so as to indicate loss of seal or tampering. The lug cap includes an upper cap portion and a depending tamper or pilfer band, each having a series of circumferentially spaced lugs. The upper cap portion and the pilfer band are joined by a plurality of frangible bridges. The container finish includes combination camming/locking projections for locking the lugs into a locked position and for separating the pilfer band from the upper cap portion by a camming action when the container is opened.
U.S. Pat. No. 5,829,613 is believed to describe a container closure system comprising a threaded cap and a threaded neck wherein the cap is affixed to the neck by direct axial application so that the mating threads slip past one another and into engagement. The cap and neck include tamper-indication means to prevent removal of the cap without activation thereof.
U.S. Pat. No. 5,449,078 is believed to describe a combination of a container and a safety cap therefor in which the safety cap has a closure plane and a circumferential outer skirt for engaging a container and has a circumferential resilient depending inner member. The container has a rigid wall having an end for engagement with the cap internally of the outer skirt. The wall is tapered from a smaller diameter portion adjacent the closure plane of the cap to a larger diameter portion remote from the closure plane of the cap. The tapered wall of the container engages internally the resilient inner member of the cap and the larger diameter portion of the wall expands the resilient inner member outwardly to provide a working seal of the container as well as a bias on the cap in a direction of removal of the cap. The combination also includes means disposed on the container remotely from the end of the rigid wall and cooperative means on the cap for preventing the cap from being removed from the container without depression of the cap on the container and rotation of the cap on the container. When the container is used as a bottle, the container includes means for providing a tamper evident seal, whereby it is evident that the contents have been sealed with a material protecting the contents of the container. Any penetration of the seal prior to the removal and destruction of the seal by the user will be evidence of the lack of integrity of the contents of the container.